Concrete pump valve with wall scraping means



March 17, 1970 A. M. SCHAIBLE ET AL 3,500,855

CONCRETE PUMP VALVE WITH WALL SCRAPING MEANS Filed May 1. 1967 2 Sheets-Sheet 1 FIG.

INVENTORS AARON M. SCHAIBLE PHILIP D. WENZEL WILSON, SETTLE a BATCHELDER. ATT'YS.

March 17,1970 MSCHNBLE m1. 5 3,500,855

CONCRETE PUMP VALVE WITH WALL SGRAPING MEANS Filed May 1. 1967 2 Sheets-Sheet 2 INVENTORS AARON M. SCHAIBLE I BY PHILIP D. WENZEL WILSON, SETTLE 8 BATCHELDER.

ATT'YS.

United States Patent 3,500,855 CONCRETE PUMP VALVE WITH WALL SCRAPING MEANS Aaron M. Schaible and Philip D. Wenze], Rockford, 111.,

assignors to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Filed May 1, 1967, Ser. No. 634,954 Int. 'Cl. F16k 3/36, 25/00, 51/00 US. Cl. 137242 3 Claims ABSTRACT OF THE DISCLOSURE A pump and valve assembly for controlling the flow of aggregate containing concrete. The valve has a piston portion reciprocated in a valve chamber and carrying a nose portion on one end thereof with a wiping shoulder intermediate the two portions to prevent collection of aggregate in the valve chamber.

Background of the invention The present invention relates generally to a pump and more particularly to an improved valve for controlling the flow of aggregate-containing material.

Prior art pumps are available wherein concrete is pumped through two separate passages from a single hopper into a single outlet where the concrete is distributed for final use. In this type of concrete pump, it is conventional to provide a working chamber in each of the passages with a reciprocating piston or pressure member operating within the working chamber to force the concrete along the passage to the outlet. Each passage also includes a pair of valve assemblies respectively located between the supply hopper and the working chamber and the working chamber and passage outlet.

During operation, one of the valves in each passage is at all times closed while the second valve is open. Thus, while one piston is being actuated to force concrete from the working chamber to the passage outlet, the valve between the working chamber and the outlet is open while the valve in the passage between the hopper and the working chamber is closed. During the work stroke of the first pressure member, the outlet of the second passage is blocked while the passage between the hopper and the working chamber is open so that concrete can be drawn into the working chamber to be subsequently forced through the outlet by the pressure member. Such a concrete pump is generally disclosed in Wilkinson et al. No. 3,198,123, and has found remarkable success in industry.

However, one of the problems with this type of concrete pump is that it is difiicult to find a valve which will effectively seal the passages to prevent separation of concrete fines and liquid from the aggregate in the mixture. One type of valve which has found partial success in the operation of a concrete pump is also disclosed in the above-mentioned patent and includes a resilient or rubber-gripping nose portion which will eifectively seat against the valve seat and envelope any aggregate which may be trapped between the valve plug and the conduit. However, such a valve has found only limited success since it has been found that after short periods of use the resilient portion of the valve plug does not remain sufliciently rigid to effectively seal the conduit to prevent any flow of liquid or fines. This means the "ice,

valve plug must be replaced after short periods of use which of course is not only costly but also time consuming.

Summary of the invention In view of the above-mentioned shortcomings of the prior art concrete pumps, it is the primary object of the present invention to provide a valve which is not subject to the disadvantages enumerated above and will satisfactorily seal aggregate-containing material efficiently, safely and expeditiously.

Another object of the present invention is to provide an improved valve plug which incorporates a wiping shoulder that will effectively prevent accumulation of any material within the valve chamber to thereby increase the service life of the entire assembly.

A further object is to provide an improved valve plug in which the parts subjected to the greatest wear and deterioration are readily replaceable.

These and other objects and features of this invention will become apparent from the following description and appended claims in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a schematic of a concrete pump incorporating the present invention;

FIGURE 2 is a perspective view of the valve of the present invention;

FIGURE 3 is a vertical sectional view of the valve assembly shown in FIGURE 2;

FIGURE 4 is a vertical sectional view of the valve assembly shown in FIGURE 3; and

FIGURE 5 is an enlarged fragmentary view of the bearing member forming part of the valve plug.

FIGURE 1 generally discloses a concrete pump 10 which includes a pair of delivery pistons or pressure members 12 and 14 respectively reciprocated in cylinders 16 and 18. The cylinder 16 defines a portion of a working chamber which communicates with a hopper 20 through a conduit 22 having a valve assembly 24 in communication therewith. The working chamber, defined in part by the cylinder 16, also is in communication with a common outlet 30 through a second conduit 32 having a valve assembly 34 in communication therewith.

Likewise, the second cylinder 18 defines a portion of a second working chamber communicating with the hopper 20 through a conduit 36 with a valve 38 controlling the flow of concrete from the hopper to the cylinder 18. A second outlet conduit 40 has a control valve 42 incorporated therein and communicates with the common outlet 30.

The pistons 12 and 14 are reciprocated within the cylinders 16 and 18, respectively, in such a manner that, as one piston is extended the second piston is simultaneously being retracted. This will provide a substantially continued flow of concrete through the outlet opening 30. For this purpose, each of the pistons has a rod 50 connected thereto which extends through a partition 52 enclosing one end of respective cylinders 16 and 18-. The free ends of the rods have second pistons 54 secured thereto each of which reciprocates in a fluid cylinder 56-. Suitable fluid pressure may be selectively admitted to the head end of the fluid cylinders 56 through conduits 58 connected to a fluid pressure source (not shown). The head ends of the fluid cylinders 56 are interconnected by a conduit 60.

Thus, by appropriate valving, one of the conduits 58 is placed in communication with a fluid sump while the second conduit is placed in communication with a pressure source. The interconnection between the head ends of the cylinder will cause the trapped fluid to be exhausted from one of the cylinders into the other cylinder to thereby simultaneously retract one piston while the second piston is being extended.

The respective pairs of valves 24, 34 and 38, 42 are actuated so that when one of the valves is open the other of the pair of valves is closed. Thus, assuming the valve 24 to be open, as the piston 12 is retracted or moved towards the left in FIGURE 1, concrete will be drawn from the hopper through the conduit 22 into the cylinder or working chamber 16. At the same time, valve 38 will be closed while valve 42 will be open and the piston 14 will be extending to force concrete from the cylinder 18 through the outlet 30.

Each of the valves 24, 34 and 38, 42 is actuated through a hydraulic cylinder 62 having fluid conduits 64, 66 communicating therewith and a piston rod 68 reciprocated therein. The piston rod 68 is connected to a valve plug 70. Suitable hydraulic and electrical circuitry may be provided to simultaneously cause valves 24, 42 to be open while valves 34 and 38 are simultaneously closed. Thus, as piston 12 is being retracted, valve 24 will be open while valve 34 will be closed to prevent flow of material from the hopper 20 into the cylinder 16. Simultaneously, piston 14 will be extending or in the discharge stroke and valve 42 will be open while valve 38 will be closed. For a more detailed description of suitable hydraulic and electric circuitry for performing the above functions, reference may be had to the above-mentioned patent which is incorporated herein by reference.

As was indicated above, this type of concrete pump has shown remarkable success but has one serious drawback in that valve assemblies heretofore utilized either did not effectively seal the conduit or had such a short service life as to be very costly to maintain. According to the invention, a control valve constructed in accordance with the teachings hereinafter set forth will provide a simple inexpensive readily serviceable structure.

The valve plugs 70 for each of the valve assemblies 24, 34, 38 and 42 are identical in construction and only one will be described in detail. Thus, the valve assembly 24 is shown in detail in FIGURES 2 through 4 and includes a first section 100 which is flanged at opposite ends to be connected to the pipes forming the respective conduits of the concrete pump shown in FIGURE 1. A section or conduit 100 defines a valve seat 102 for the valve plug 7 0.

An opening is defined in the upper end of the section 100 which communicates with one end of a sleeve 104 defining the valve chamber for the reciprocating valve plug 70. The sleeve 104 has a slotted clean-out adapter 106 at the upper end thereof with the sleeve 104 and adapter 106 held in assembled relation by bolts 108 having one end secured to the section 100 and the opposite ends extending through a flange 110 formed on the lower end of the cylinder 62. The entire plug valve assembly 24 is held in assembled position by nuts 112 threadedly received on the ends of the bolts 108;

The valve plug 70 is shown in detail in FIGURES 3 and 4 and includes a cylindrical guide portion 120 having a threaded opening 122 in the upper end thereof which threadedly receives the end of the piston rod 68. A lock nut 123 is preferably provided to maintain the cylindrical guide portion 120 on the piston rod 68. The cylindrical guide portion 120 has a pair of recesses 124 which receive bearing members 126. The bearing members 126 are preferably a Nylatron material and have a plurality of longitudinal grooves 128, as shown in FIG- URE 5, for a purpose to be described later.

The lower end of the section 120 has a cylindrical relieved area or reduced diam ter por ion 130 f re i ing sealing means 132. The sealing means preferably includes a plurality of V-shaped packing rings 134 and male and female adapters 136 and 138, respectively. The entire sealing means 132 is held in the relieved portion by a ring 139.

The guide portion 120 also has a piston or first portion 140 removably secured to the lower end thereof by bolts 142 extending through openings in the guide portion 120 and threadedly received in openings defined in the portion 140. The portion or piston 140 has a recess 144 for receiving a sleeve 146 the outer diameter of which is equal to the diameter of the piston. The lower end of the sleeve terminates in a flat portion substantially perpendicular to the outer surfaces of the sleeve to define a shoulder 148, for a purpose to be described later.

A nose portion 150 is removably secured to the lower end of the piston 140. For this purpose, the piston 140 has an opening 152 in the lower end thereof which receives a complementary extension 154 integral with the nose portion 150. The extension 154 has a threaded opening 156 in the upper end thereof which receives a bolt 158 for fixedly securing the nose portion to the piston. As clearly shown in FIGURE 4, the lower or distal end of the nose portion 150 is dome shaped to define a surface 160 contoured to correspond to the contour of the valve seat 102 defined in the section 100. The upper end 162 of the nose portion is cylindrical or circular and has a diameter less than the outer diameter of the piston 140 to define a recessed portion 162 intermediate the inner surface of the sleeve and the outer surface of the nose portion.

The operation and advantages of the valve will be readily apparent from the above description. Thus, during the reciprocation of the plug 70 within the sleeve 104, the abrupt shoulder defined by the end of the sleeve 146 will continuously clean or wipe any debris or fine particles which may cling to the inner surface of the valve chamber or sleeve 104. This will substantially reduce or practically eliminate abrasion of the inner surface of the valve chamber and the other surface of the valve plug to thereby considerably increase the service life of these parts. The thickness of the shoulder 148 is preferably on the order of %inch.

Furthermore, the dome shaped end of the nose portion will considerably reduce any wedging action between the end of the valve plug and the valve seat. Stated another way, the dome shaped end will force the larger particles forming a part of the concrete mixture axially along the opening defined in the section 100 so that the valve plug may properly seat. Even if the valve plug traps some of the concrete mixture during its closing thereof, this will not render the valve inoperative for its intended purposes, since, the normal mixtures of concrete material are sufficiently plastic so that any material which may be trapped between the end of the valve plug and the valve seat will tend to pack or stow in the passage which may be left if the valve plug does not effectively seat. Due to the compressive forces applied by the hydraulic fluid to the valve plug, the material which may be trapped below the valve plug will tend to compress the plastic like material trapped below the valve plug and will force the majority of the liquid out of the mixture. Thus, contrary to previously stated beliefs, the concrete mixture can readily be utilized for providing an effective seal even if the valve plug does not properly seat due to small aggregate particles which may be trapped between the valve seat and the valve plug. Of course, during the working cycle of the pressure member or piston 12 or 14, any material which may be packed in the valve seat will be forced along the conduit leading to the outlet passage so that during every pressure stroke of either of the pistons 12 or 14 will effectively clean any concrete which has been packed in the valve seats.

Of course by making the valve plug of a plurality of removable sections, any parts which may be subjected to the greatest amount of wear, such as the nose portion 150 or the sleeve 146 can readily be replaced and the remaining portion of the valve can be used to thereby substantially decrease the cost of servicing the valve plug. Furthermore, the dome shaped nose portion will allow the valve to properly seat irrespective of the rotational position of the plug within the valve chamber.

The upper portion or guide 120 of the valve plug will not be subjected to any contacting forces on the sleeve due to the bearings 126 and the packing means 132. The V-shaped packing rings 134 will elfectively prevent any material, whose flow is to be controlled by the valve plug, from flowing past the packing. However, should any of the fine material pass the seals formed by the V-sha-ped packing, this material can readily move out of the valve plug through the elongated or longitudinal grooves 128 formed in the bearings 126 and thereafter move out of the valve chamber through the clean-out adapter 106.

All of the parts of the valve plug are formed of a metallic material to withstand the extreme forces applied thereto and the valve sleeve or chamber 104 as well as the sleeve 146 are preferably made of a relatively hard steel, such as stainless steel.

Thus, it can readily be appreciated that the valve of the present invention provides an effective way of sealing or closing an aggregate containing material flowing in a conduit and the service life of the various parts of the assembly will be considerably increased while at the same time the cost of maintenance for the valve will be considerably reduced.

We claim:

1. A valve assembly for controlling the flow of material containing discrete particles through a passageway incorporating a valve seat therein, the valve assembly comprising a guideway; a valve slidable back and forth in the guideway; the valve having a nose portion of substantially the same shape as the valve seat, and adaptable to engage the valve seat to prevent flow of material through the passageway, a guide portion, a wiping edge between the guide portion and the nose portion, the wiping edge being engageable with the guideway to wipe discrete particles from the surface thereof during reciprocation of the valve, and sealing means carried by the valve for preventing the flow of material thereby from the nose portion, the guide portion having a bearing surface engageable with the guideway for providing guiding support for the valve, the bearing surface having an axially extending groove to permit any material that is passed by the sealing means to flow therethrough and away from the valve so as to not interfere with the reciprocation thereof in the guideway.

2. A valve assembly as described in claim 1, wherein the nose portion of the valve is dome-shaped and the sealing means is a series of annular packing rings surrounding the valve.

3.,A valve assembly for controlling the flow of material containing discrete particles through a passageway incorporating a valve seat comprising of a guideway, a cylindrical shaped valve reciprocal in the guideway, the valve including a nose portion having a configuration complementary to that of the valve seat and engageable therewith to prevent the flow of material through the passageway, a guide portion, a piston portion between the guide .and the nose portions, the piston portion including a sleeve providing with a wiping edge engageable with the guideway so as to wipe discrete particles from the surface thereof during reciprocation of that valve, sealing rings carried by the guide portion engageable with the guideway to prevent the flow of material thereby, the guide portion including a bearing element engageable with the guideway to provide guiding support for the valve and having in the surface thereof axially extending grooves adapted to pass from the valve and to a cleaning area, any of the material escaping by the sealing rings.

References Cited UNITED STATES PATENTS 1,621,638 3/1927 McIntyre l37242 2,213,998 9/1940 Sifkovitz 137-242 2,401,112 5/ 1946 Saunders 251168 2,982,295 5/1961 Williams 137242 3,036,587 5/ 1962 Silver 137-244 X 3,315,696 5/1967 Hunter 137-242 X 3,409,035 11/1968 Miller 137-242 CLARENCE R. GORDON, Primary Examiner US. Cl. X.R. 251-189, 357 

